1. Field of the Invention
The present invention relates in general to secondary electrolytic cells, and more particularly, to lithium ion electrolytic cells with an inorganic binder and a process for fabricating same.
2. Background Art
Lithium ion electrolytic cells (such as lithium ion secondary batteries) have been known in the art for several years. Furthermore, lithium cells which utilize anode and cathode materials binded with organic polymers, such as PVDF, EPDM, and some fluorine-containing copolymers, are similarly well known in the art.
While the use of organic binders is well established in lithium ion cells--they nonetheless have some known limitations in terms of cell/battery performance. Indeed, when organic binders are utilized, physical and/or chemical instability can result due to, for example, solubility of a portion of the binder with the electrolyte--inasmuch as electrolytes used in lithium ion batteries are also made of organic compounds. Accordingly, such solubility can result in premature degradation of the binder (and electrode), and, in turn loss of adhesion of the active material to the associated current collector/electrode.
Additionally, when an organic binder is used to fabricate an electrode and to have it adhere to the current collector, it becomes necessary to use organic solvents--when actually mixing the binder with the active material paste/coating. Accordingly, after applying a coating of the mixed active material/binder to the current collector, and prior to completed fabrication of the cell, any remaining organic solvent must be removed. Failure to do so could result in a substantial loss of cell capacity and diminished cycle life.
It is thus an object of the present invention to provide a lithium ion electrolytic cell having a binder material with excellent physical and chemical stability.
It is further the object of the present invention to provide a unique process for preparing an electrode for use with an inorganic binder.
These and other objects will become apparent in light of the present Specification, Claims and Drawings.